Abstract: Method and apparatus for providing liners in manhole assemblies, which liner is comprised of a plurality of liner sections joined together to form the inner corrosion resistant surface of each manhole member. The liner section define the inner surface of the manhole member being molded. Cast material is poured into the mold and allowed to set. The liner surface engaging the cast material contains integral substantially T-shaped projections which anchor the liner sections to the cast member. The tops and bottoms of each liner section extend around the surface of the section engaging the next adjacent section joined thereto to prevent toxic materials from reaching a cast material. The liner sections are theroplastic vacuum formed whereby the sheet forming the liner section is drawn against substantially T-shaped strips arranged upon the mold member within the vacuum thermo-forming equipment to provide the aforementioned integral T-shaped anchoring projections.

Abstract: A hollow, flexible, bendable, cylindrical-shaped, hat-like sleeve is water-tightly joined with the upper end of the riser section of a manhole structure. The free end of the sleeve is trimmed so that its upper edge fits beneath the shoulder of the frame supporting the manhole cover to prevent subsurface water from entering into the manhole interior through the regions between the manhole cover supporting frame and the top of the riser section, which is usually fitted with adjustment rings to bring the manhole cover frame up to grade. The sleeve is easily cut to any height to accommodate either a greater or lesser number of height adjustment rings. The sleeve flange is cast into the riser section. The sleeve may be folded into itself to significantly lower its profile to expedite handling, transportation and assembly. A plastic clamping band may be placed into the interior of the sleeve to water-tightly join the upper end of the sleeve to the manhole cover support frame.

Abstract: A hollow, flexible, bendable, cylindrical-shaped, hat-like sleeve is water-tightly joined with the upper end of the riser section of a manhole structure. The free end of the sleeve is trimmed so that its upper edge fits beneath the shoulder of the frame supporting the manhole cover to prevent subsurface water from entering into the manhole interior through the regions between the manhole cover supporting frame and the top of the riser section, which is usually fitted with adjustment rings to bring the manhole cover frame up to grade. The sleeve is easily cut to any height to accommodate either a greater or lesser number of height adjustment rings. The sleeve flange is cast into the riser section. The sleeve may be folded into itself to significantly lower its profile to expedite handling, transportation and assembly. A plastic clamping band may be placed into the interior of the sleeve to water-tightly join the upper end of the sleeve to the manhole cover support frame.

Abstract: A hollow cylindrical-shaped, hat-like sleeve is water-tightly joined with the upper end of the riser section of a manhole structure. The free end of the sleeve is trimmed so that its upper edge fits beneath the shoulder of the frame supporting the manhole cover to prevent subsurface water from entering into the manhole interior through the regions between the manhole cover supporting frame and the top of the riser section, which is usually fitted with adjustment rings to bring the manhole cover frame up to grade. The sleeve is easily cut to any height to accommodate either a greater or lesser number of height adjustment rings. The sleeve flange may be cast into the riser section, or alternatively be placed upon the riser section and water-tightly sealed in place by gaskets. The sleeve flange may be replaced by a gasket-like water stop arranged about the lower end of the sleeve and joined thereto by a suitable waterproof rubber adhesive.